REMOTELY CONTROLLED UNDERWATER VEHICLES FOR INSPECTIONS

Since the severities, unmanned remotely operated underwater vehicles h ave been used increasingly by offshore industries for inspection and m aintenance of platforms and pipelines. Technical development has turne d ''submerged cameras'' into sophisticated underwater handling systems equipped with manipulators and a variety of sensors. As the applicati ons and depths of operation increased so did the dimensions and the we ight of these remotely operated vehicles (ROVs). The range of potentia l uses became wider, and the wish arose to adapt these vehicles to var ious different applications. For some of the commercially operated veh icles, manufacturers offer e.g., MasterSlave manipulator arms or Sonar sensors as optional extras. On the other hand the universally applica ble modular ROV has not so far grown beyond the conceptual design stag e. As ROVs are employed especially in locations where extreme environm ental conditions make the work of divers uneconomical, small inspectio n vehicles have been employed also in the flooded sections of nuclear installations. In the light of the conditions prevailing in that envir onment some existing vehicles were scaled down and equipped with radia tion-resistant underwater cameras. The Institute for Materials Studies of the University of Hanover-developed small ROVs specifically for ri se in nuclear facilities, with these boundary conditions being taken i nto consideration: Failsafe characteristics; design allowing easy deco ntamination; small dimensions; high mobility for precise maneuvers in constricted spaces; low water depths not exceeding 30 m; short tooling times; reliable retrievability of the vehicle.